Well Matt - since it happens when turning my extemeley novice thought is it
has something to do with your power steering pump. Another thing to consider
is possibly your alternator is getting to the end of its life - I had one
that did that for a while although it was more of a whine than a hum.

That's just what comes to mind - I'm certain those with more knowledge will
be more reliable in their diagnosis.

--
Thanks,

Jeff
'90 Carat (Grover)
'86 (We call this one Parts)
'78 Bus (Melissa) Patty's Bus